1. Field of the Invention
The present invention relates to esters of 2-propylheptanol, to the use of esters of 2-propylheptanol in cosmetic and/or pharmaceutical preparations, and to a process for the production of such esters.
2. Background and Related Art
Cosmetic hair and skin-care emulsions are expected by the consumer to satisfy a number of requirements. Apart from the cleansing and caring effects which determine the particular application, importance is attributed to such diverse parameters as the highest possible dermatological compatibility, good lipid-layer-enhancing properties, elegant appearance, optimal sensory impression and shelf life.
Besides a number of surfactants, cosmetic hair- and skin-care preparations generally contain, above all, oil components and water. The oil components (emollients) used include, for example, hydrocarbons, ester oils and vegetable and animal oils/fats/waxes. In order to satisfy increasingly stringent market requirements in regard to sensory properties and optimal dermatological compatibility, new oil components and emulsifier mixtures are being continuously developed and tested. In particular, because of the importance of ester oils, including branched ester oils that impart a “lighter” skin feel in cosmetic products, ester oils are the subject of intensive research and new processes for their production are being continuously developed. The use of 2-methyl-1,3-propanediol monoesters is described, for example, in DE 101 60 681; the use of 2-methyl-1,3-propanediol diesters is described in DE 101 60 682.
The problem addressed by the present invention was to provide new ester oils, preferably liquid at 20° C. for cosmetic applications, which would have an improved profile in regard to their sensory properties (lightness, non-greasy skin feel, softness, spreadability, absorption, distribution behavior, oiliness) and which could be incorporated in a number of cosmetic formulations. Hydrolysis stability of these esters, their capacity for formulation at low pH values, their ability to be incorporated both in water-in-oil and in oil-in-water formulations, and their compatibility, in particular, with crystalline UV filters, pigments, antiperspirants, salts and silicones were also to be of significance. It has now surprisingly been found that esters of 2-propylheptanol (some of which, with their production methods have already been known from DE 103 05 562 (published United States Patent Application 2007/027244, Schar et al), but for the totally different and unrelated application as polymer additives, and from Japanese Patent 05070403 (Chisso Corporation), but for use as acrylic binders with improved low-temperature adhesiveness for engines) lead to sensorially-light products.